METHOD FOR DIAGNOSING FAILURE OF COMMON RAIL SYSTEM

摘要

A fault diagnosis method of a common rail system according to the present invention comprises: a rail pressure filling step in which a controller fills the common rail to a first target pressure; After the rail pressure filling step, a rail pressure maintaining step of the controller to maintain the common rail at a first target pressure for a first set time; As a result of performing the rail pressure maintenance step, when the common rail is maintained at the first target pressure for the first set time, the control unit closes the rail pressure control valve and turns off the engine to lower the common rail pressure. step; a rail pressure monitoring step in which a controller measures a time taken for the common rail to reach a second target pressure set smaller than the first target pressure from the time when the rail pressure lowering step is started; After the rail pressure monitoring step, a time comparison step in which the control unit compares the difference value obtained by subtracting the measured required time from a preset reference time with a reference value; and an oil leakage warning step in which the controller outputs a warning signal to the diagnostic apparatus when the difference value exceeds the reference value as a result of performing the time comparison step.